Abstract
Quadratic functional equation was used to characterize inner product spaces. Several other functional equations were also used to characterize inner product spaces. In this paper we solve five funtional equations (1), (2), (3), (4), and (5) connected to quadratic functional equation and inner product spaces.
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Dedicated to Prof. J. Aczel on the occasion of his 70th birthday.
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Kannappan, P.L. Quadratic Functional Equation and Inner Product Spaces. Results. Math. 27, 368–372 (1995). https://doi.org/10.1007/BF03322841
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DOI: https://doi.org/10.1007/BF03322841